The system fonts are greatly improved. Tweaked the spacing and layout of much of the interface. The new features are useful (improved battery life, profiles, etc.). Some of the apps are redesigned (especially the Amazon Shopping app) and I think they are mostly a plus.

Also, a lot of unfinished little bits here and there (like swiping up in the Videos app causing a little bar to appear at the bottom of the screen) have been cleaned up and the presentation is much improved.

I like the update quite a bit. Much nicer formatting. Clean fonts and look. The battery life is greatly improved with the "suspend" thing. Now my kindle fire doesn't run down on me so quickly when it's in sleep mode.